The U.S. Tax Court is ordering the Internal Revenue Service to refund at least $30 million to as many as 1,173 users of a tax shelter promoted by a Honolulu man because the agency's lawyers bribed pivotal witnesses, Bloomberg News reported.

The court last week issued a 137-page ruling that requires the IRS to give the same deal to those taxpayers as it did to the witnesses in a test case tried years ago and imposes sanctions on the agency for perpetrating a "fraud on the court," Bloomberg reported.

The news service said the ruling may close the book on a legal saga over the agency's conduct in prosecuting users of a tax shelter promoted by a Honolulu resident, Henry Kersting, Bloomberg said. He helped clients, mostly airline pilots, generate artificial interest deductions in the early 1980s.